Electrical relay with contact multiplying movement



J. HIGH, JR

Original Filed Nov. 13, 1944 INVENTOR nM. Hi

J BY M ATTORND ELECTRICAL RELAY WITH CONTACT MULTIPLYING MOVEMENT Dec.13, 1949 /r T w H {a 4 m \F. .MUI 5 r n I 6 O a 1 M m m. a m m Fig 5,

Patented Dec. 13, 1949 ELECTRICAL RELAY WITH CONTACT MULTIPLYINGMOVEMENT John M. High, J r., Riverdale on the Hudson, N. Y.,

assignor to Signal Engineering & Manufacturing Company, New York, N. Y.,a corporation of Massachusetts Original application November 13, 1944,Serial No. 563,281. Divided and this application February '1, 1946,Serial No. 646,045

4 Claims. 1

- The present invention relates to electrical circuit controllingdevices of the type commonly known as relays, and is a division of myoriginal application Serial No. 563,281, filed November 13, 1944, for anElectronic relay control circuit.

The device of the present application has for its object to provide arelay of novel form and particularly adapted for use in connection witha thermionic vacuum tube circuit, to the extent that the actuating coilsof the relay are included in and form part of the tube circuit. Otherand further objects of the invention are to provide a relay of extremesensitivity,, requiring no springs or mechanical bias. and free frommechanical resonance efiects and chatter.

The relay of the present application is characterized by a, fast makeand break, with .relatively wide separation between the current carrying parts, and in which the actuating armature is extremely stable andrelatively insensitive to jarring in either open or closed position, ofthe relay contacts. The improved relay is further I characterized by awide range of adjustment to meet various operating conditions.

The above and other advantageous features of the invention willhereinafter more fully appear from the following description withreference to the accompanying drawings, in which:

Fig. 1 is a side view of a relay embodying the invention.

Fig. 2 is a view in front elevation of the relay shown in Fig. 1.

Fig. 3 is a side view similar to Fig. 1, as viewed from the oppositeside.

Fig. 4 is a circuit diagram illustrating one use upon which are directlymounted coils I and 2,-

and each of these coils is provided with acore of magnetic material.

Preferably.'suitable means are provided for adjusting either or both ofcores Ia and 2a longitudinally of coils I and 2, and one form which suchadjustment may take is indicated in Fig. 1,

in which there is shown a screw 8 freely received within a ho.'e in base1, and threaded within core Ia or 2a in such a manner that as the screw8 I 2 is rotated the corresponding core moves longitudinally within thecoil I or 2.

The armature 3 is carried by a bifurcated fulcrum bracket 9, which mayhave outwardly extending arms I0 and II, these arms carrying set screwsI2 and I3, and lock nuts I4 and I5, by means of which the rotationalmovement of armature 3 on its shaft or pivot 4 may be very closelyadjusted between limits. Fixed to armature 3 is an arm I5 extendingoutwardly therefrom, this arm carrying at its outer extremity a contactII. It will be seen that as armature 3 rocks on its pivot 4, arm I6 willbe carried thereby, and contact I! will describe an arc about pointpivot 4.

Likewise, secured to pivot 4 and thereby to armature 3 there is provideda relatively large gear I8, this gear engaging a small pinion I9 securedto a shaft 20, mounted for rotation in the bifurcated bracket 9. Thisshaft 20 carries an outwardly extending arm 2I provided at its end witha contact 22 adapted to engage with contact II. It will be understoodthat with this construction both contacts I1 and 22 are movable, and ifFig. 1 is considered as showing the position of the relay with armature3 at the full extent of its counter-clockwise movement, then as thearmature moves clockwise, contact II will swing in an arc clockwiseabout pivot 4 and contact 22 will swing in an arc counter-clockwiseabout pivot 20, and the motion of contact 22 will be in excess of themotion of contact H in the ratio of the number of teeth on gear I8 tothe number of teeth on pinion I9.

Thus, a relatively large movement occurs between contacts I1 and 22,with a relatively small movement of the armature 3, and this may be inthe ratio of the order of 5 to 1; that is to say, it is a relativelysimple matter to provide a motion of 1%" between contacts I1 and 22 witha motion of only /100 between pole piece 5 and core Ia.

When using the relay with the tube 23 shown in Fig. 4, the tube 23 isoperated rather differently than in conventional practice. The constantsare so chosen that under normal conditions; i. e., with no soundsfalling upon the microphone 24, a considerable plate current is drawn.which flows through coil I, and this current under usual conditions maybe as much as 20 milliamperes.

The voltage applied to screen 23sg is made approximately the same asthat upon plate 23a,

but the screen current under such conditions is relatively low, and maybe of the order of not more than 2 milliamperes. This may be achieved byadjustment of condenser 25, which may be of the order of 20 microfarads,and condensers 2G and 21, which may be of the same order, and byselection the value of resistor 28, which may be of the order of 100ohms. Condensers 25, 20 and 21 may be made variable if desired, althoughfor economy fixed condensers may be used.

Inductances, as represented by relay coils I and 2, are not critical butshould be of high im- Pedance and of the order of the internal impedanceof the tube in the circuits in which they are connected. Verysatisfactory results have been obtained with coils having an inductanceof 12 henries, D. C. resistance of 5,110 ohms, wound with 21,000 turnsof #42 wire. Under such conditions the relay will remain in thecondition shown in Fig. 1; i. e., with the contacts l1 and 22 open tothe full extent of their swing.

If, now, noise or sounds impinge on the microphone 24, as will beunderstood, they produce an alternating or fluctuating voltage, and thisis impressed through the transformer windings 29 and 30 upon the inputelectrodes of tube 23. When this occurs, the direct plate current drawnby anode 23a sharply decreases and may under certain conditions decreasealmost 'or to zero, while simultaneously the direct current drawn byscreen grid 23sg increases many times; for in stance, to or moremilliamperes.

The result of this is that the pull of coil I on pole piece 5 decreasesto little or nothing, whereas the pull of coil 2 upon pole'piece 6sharply increases, and the relay closes with an extremely rapid action.Since there is no spring associated with the armature as in conventionalrelays, no substantial mechanical reasonance eflects are encountered asin ordinary relays, and there is little or no tendency to bounce,chatter, and are.

As long as the microphone continues to pick up sustained sounds, therelay will remain with its contacts in closed position since the platecurrent through coil l remains very small and the screen grid currentthrough coil 2 remains relatively large. when the microphone ceases topick up sounds, the circuit reverts to former conditions; that is, thecontrol electrode 23g returns to its normal potential, the screencurrent through coil 2 drops to a very small value, the plate currentthrough coil i returns to its normal value, and this action likewisetakes place very rapidly, the relay then returning very quickly to openposition.

Since in either open or closed position the relay contacts I! and 22 areheld at one extremity or the other of their movement by flow of currentin either coil i or coil 2, and no spring action is involved, the relayis extremely insensitive to mechanical jars and vibration and thus isrelatively free from spurious openings or closings to which conventionalrelays are quite sensitive.

A particular advantage of the arrangement of Fig. 4 is that the relay issubstantially independent of fluctuations in the supply voltage, sinceboth the screen and plate circuits are affected to the same degree byany change in supply voltage. The value of current in coils i and 2 mayvary widely with different tubes or even the same tube under difierentoperating conditions, provided coils i and 2 are properly designed tocarry the maximum current without damage. Likewise, various sizes ofcontact points may be employed and the speed of make and break may be soregulated as to provide the desired action for any particular type andkind of contact employed.

While for purposes of illustration the above described differentialoperation of the relay coils l and 2 has been with reference to themaking and breaking of a circuit through contacts l1 and 22. it is clearthat the movement of the armatu're 3 about its pivot 4 may as readily beemployed to perform a purely mechanical function, as by actuating alever or link forming part of an associated mechanism not necessarilyconcerned with the flow of electrical current. For instance, themovements of the armature 3 in response to impulses received from themicrophone might be readily employed to control the operation ornonoperation of a clockwork mechanism of an alarm device.

Also, I have applied my invention in the operation of toys andnovelties. An example of this is a flag-raising toy wherein the relaycontacts are in series with the circuit of a ratchet motor operating thehalyards of a small flag attached to a flagpole at the top of aminiature fort. By properly adjusting the constants and voltages of thetube, singing 'or whistling reveille or other desired music may be madeto cause the raising of the flag.

Another application which I have made is the control of a dancing figurein time with music. In this instance there may be provided anarticulated mannequin having a solenoid having its core arranged andattached to the Jointed arms and legs so as to deliver a pull to themwhen the relay is closed. With such an arrangement, pickup by themicrophone of music being played orsung will cause the mannequin todance in time with the music.

While my invention is of particular utility in providing for operationof a relay in response to rapidly fluctuating or pulsating impulses, it

will also be of considerable utility where steady biasing voltages areused for relay operation, because of its sensitivity, freedom fromchatter and arcing, and insensitivity to jars.

I claim:

1. In a relay, in combination, a pivoted armature, an arm extendingtherefrom carrying a contact, a gear secured to said armature, a secondarm mounted for rotation toward and away from the first mentioned armand carrying a contact adapted to engage the first mentioned contact,and a pinion secured to said second arm meshing with said gear.

2. In a relay, in combination, a pivoted armature', magnetic means formoving said armature, a first contact-carrying arm mounted upon andmovable with said armature, a second contactcarrying arm mountedadjacent said armature for movement toward and away from said first armthereby to close and open said contacts, and motion-multiplying meansconnected to said second arm and actuated by said armature.

3. In a relay, in combination, a pair of electromagnets, an armaturepivotally mounted between and disposed in magnetic relation with saidelectromagnets, a first contact-carrying arm mounted upon and movablewith said armature, a second contact-carrying arm mounted adjacent saidarmature for movement toward and away from said first arm thereby toclose and open said contacts, and motion-multiplying means connected tosaid second arm and actuated by said armature.

4. In a relay, in combination, a pair of electromagnets, an armaturepivotally mounted between and disposed in magnetic relation with saidelectromagnets, a first contact-carrying arm mounted upon and movablewith said armature, a second contact-carrying arm mounted adjacent saidarmature for movement toward and away from 5 6 said first arm thereby toclose and open said UNITED STATES PATENTS contacts, a. first gearsecured to iald seccnd am; Number Name Date and a second gear secured tosa :1 arma. ure an 273.728 Hamilton Mar. 13, 1883 meshing with saidfirst gear thereby to actua e 329,808 Bums NW 3, 1885 said second arm inrespon to movements 6 384,323 ne, June 12,1888 said armature. 626,606

Gallegos June 6, 1899 JOHN HIGH' 754,689 Pearne et a1 Mar. 15, 19041,302,284 Beall Apr. 29, 1919 REFERENCES (MED 10 1,748,917 Leake Feb.25, 1930 The following references are of record in th 1,954,365 ReichApr. 10, 1934 file of this patent: 2,092,560 Runaldue Sept. '7, 1937

